The present invention relates to a washing machine for the washing of fabric articles such as clothes, and more particularly to a washing machine of the "wobble" type. The wobble washer essentially uses a unitary basket which is wobbled to cause relative motion between the liquid and the fabrics contained therein.
U.S. Pat. No. 2,555,400 to De Remer discloses a wobble type of washing machine having a basket mounted to a rotor shaft which is coupled to the input drive shaft by a universal joint. The weight of the clothes and liquid in the basket causes the shaft to tilt and rest against inverted conical walls of a gyrator which then moves the rotor shaft in a conical path so that the axis of the basket describes an inverted cone having an apex beneath the basket. The rotor shaft is moved toward a vertical position by a combination of spring forces and gyroscopic forces for the spin mode of operation.
Other examples of wobble type machines include that shown in U.S. Pat. No. 2,549,824 to Kost where the tub axis is made to wobble in a conical path while the tub is oscillated about its own axis. The washing motion is accomplished by an inclined post and a ball pivot extended into a cocked off-center bearing in a worm wheel. An attached slide link provides angular displacement of the post about its axis. U.S. Pat. No. 3,263,459 to Bochan et al, shows a basket eccentrically mounted on the upper end of the drive shaft which extends upwardly within the tub. During wash, the drive shaft rotates while a clutch mechanism prevents rotation of the basket. The rotation of the drive shaft thus imparts a wobble motion to the basket and the fabric articles contained therein. The basket remains canted during spin. Finally, U.S. Pat. No. 2,432,766 to Kirby describes a washing machine in which the basket executes an orbital movement while at the same time being rotated about its own axis. Although the degree of gyration appears to be much less than in a true wobble type washer, the motion is still of a wobble type.
In order to minimize stresses on the support suspension system for the basket, as well as to minimize vibration during spin, it is desirable to center the basket during spin to permit rotation about its own axis. Of the wobble type machines hereinbefore referred to, only the De Remer machine makes provision for centering the basket for spin. Even in De Remer, the spin typically is somewhat off center, causing its axis to precess as it relies on gyroscopic forces balanced by spring forces for centering during spin. It is desirable to correct this deficiency in the art by providing a simple relatively inexpensive mechanism for wobble washers which would cant the basket to provide wobble motion during wash cycles and reliably center the basket for rotation about its own axis during spin cycles.
It is therefore an object of the present invention to provide a washing machine of the wobble type with a mounting arrangement which provides wobble motion of the basket during wash periods and vertically aligns and centers the basket for spin about its own axis during spin periods.
It is a further object of the present invention to provide a mounting structure for a washing machine of the wobble type which cants the central axis of the wash basket relative to a substantially vertical reference axis during wash periods to impart a wobble motion to the basket as the drive shaft rotates in one direction, and aligns the central basket axis with the reference axis during spin periods for rotation of the basket about its own axis when the drive shaft rotates in the opposite direction.